Composition roof



(No Model.) Y

J. PHOFMAN. GOMPOSITON R001".

No. 285,131. Patented Sept. 18,` 1883.

purpose.

UNITED STATES PATENT OFFICE.

JOHN F. HOFFMAN, OF CINCINNATI, OHIO.

COMPOSITION ROOF.

SPECIFICATION forming' part of Iietters Patent No. 285,131, datedSepteniber 18, 1883.

Application filed June 25, 1888. (N o model.)

To a/ZZ whom it may concern: e Be it known that I, JOHN F. HOFFMAN, acitizen of the United States, residing at Gincinnati, in the county ofHamilton and State of Ohio, have invented certain new and usefulImprovements in Composition Roofs, of which the following is aspecification, reference being had therein to the accompanying drawings.

vThe object of my invention is to construct composition roofs in such amanner as to afford secure and water-tight joints at the junctions ofthe various'sheets usually employed for this I accomplish this result bycementing together three sheets or layers of tarred paper or othersuitable felt or fabric, the under sheet being about four inchesnarrower than the intermediate and outer sheets. Fur# secure under allconditions of weather, said joint projecting such a slight distanceabove the general level of the roof as to present no 'obstacle whateverto the free shedding of water, snow, Sac., as hereinafter more fullydescribed, and pointed out in the claims.

In theV annexed drawings, Figurel is a perspective view, showing theunder side of my improved roofing sheet. Fig. 2 shows the method offastening the first sheet to the roof. Fig. 3 shows the method ofinterlocking the flaps of the second sheet with the flaps of the firstsheet. Fig.4is an enlarged section through said engaged iiaps.

.As more clearly seen in Fig. l, each sheet of my roofing material ispreferably composed of an outer layer, A, an intermediate layer, B, andan inner or bottom layer C. These various layers may be composed eitherof thick paper, or` canvas, or felting, or any other dexible fabric thatcan be securely cemented together and used for roofing and similarpurposes. Furthermore, these layers or webs may be of any length andwidth that will allow them to be conveniently handled and applied. Theinner layer C is usually'from four to six inches narrower than the otherlayers, A B, although all of these pieces A B C are cemented together,so as to form practically a single sheet. rIhe cement, however, is soapplied to said layers A B as to leave their opposite margins, a a and bb', perfectly free, thereby converting these membersinto ilexible flapswhich extend inwardly about as far as the edges of the bottom layer C.To cover a roof the first sheet is so applied thereto as to bring thelower edge of the bottom layer, C, in line with the margin of sheathingD, after which act the flaps a b of the other layers, A B, are turneddown and nailed or otherwise secured at E, as seen in Fig. 2, referenceto which illustration shows that the other flaps, a b, of the layers A Bare free. The second sheet, A B C', is then laid down parallel with thefirst sheet, A B C, the hap b of the layer B being fitted snugly againstthe lower edge of the bottom layer C of 4this second sheet, andthe iiapb of layer B is lapped over said flap b. Cement is now applied to theupper surface of this latter ilap b, and the flap a of layer A is thenunited thereto. The nails or other retaining devices F (seen in Fig. 4)are then driven through these cemented aps into the sheathing D.Finally, cement is spread upon the upper surface of flap a', and theliap a of layer A being united thereto, the joint is complete, and thefinishing-coat of tar, pitch,

cement, or paint may be added. -This first joint of the roof is seen inFig. 3, which illustration also shows that the aps c b at the uppermargins of layers A B are free to be interlocked with the appropriateaps of the third sheet in the manner just described. Beference to Fig. 4shows that although the joint is composed of no less than fourthicknesses of material, yet the upper surface of said joint projectsbut very little above the general level of the roof, and hence there areno serious ledges in the same for water and snow to lodge against. Thisslight projection of the joint is due tothe fact that the bottom layers,C C',

are narrower than the other layers, A B A B', of their respectivesheets, for it is evident that IOO if said layers C C extended the fullwidth of the sheet the joint would be composed of six thicknesses ofmaterial.

If desired, each sheet of the roofing material may be composed of fouror five or more layers; but this construction would be very unhandy toapply, and as all the advantages of such an arrangement could beobtained by simply increasing the thickness of the layers, it ispreferred to use three of them. Again, by thus increasing the thicknessof the fabric, two layers might be sufficient in some cases, and theright is reserved of modifying the invention to this extent. Finally,the separate layers A B C may be saturated with any suitablewater-repellent before being incorporated into one sheet.

I claim as my invention- 1. As a new article of manufacture, a sheet forcomposition roofs, which sheet is composed of a lower layer of felt orother suitable material, upon which is cemented one or more wider layershaving free marginal flaps projecting beyond. both edges of said@ loweror narrow layer, and adapted to interlock with the marginal flaps of theadjoining sheet, as herein described. v

2. A composition roof` composed of a sheet, A aa B b b C, cementedtogether, as herein described, the fiaps a b thereof being interlockedwith the flaps a b of the other sheet, A a a B b bm. C, as explained,nails or other retaining devices, F, being driven through these flapsinto the sheathing or other backing, as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN F. HOFFMAN.

Witnesses:

JAMEs H. LAYMAN, HENRY C. BRADLEY.

